I just use a handheld belt sander and a bench vise. I use a torpedo level to level the rails as I dress them and, once they are clean and level I make a final pass parallel to the rails which slicks them up. Quick and efficient....and safe. What I want, also, is one of those belt/disc sanders. I wish they made one with a fence that goes along the length of the belt so that I could put the bar against the fence to keep it perpendicular to the belt.